'People want a simple narrative; they want a magic young prince to save them. You can see this with Barack Obama'. Photograph: Frank Baron

Just over five years ago, Michael Burleigh did the unthinkable. He walked away from academia. No jumping, no pushing - just walking. With his career on a high after winning the Samuel Johnson prize for The Third Reich: A New History, and after more than two decades teaching at Oxford, the London School of Economics and Cardiff - not forgetting visiting posts at Rutgers and Stanford in the US - he decided to jack it all in.

"The crap had begun to take over," he laughs bleakly. "I had always promised myself I would never become the kind of academic who surrounded himself with cronies. Yet the more prominent you become, the more people tend to gravitate towards you, and you can become a guru-like figure to them, whether you want to or not. You take on postgraduates and PhD students, and then you try to help find them academic posts and you end up with clones in the institutional apparatus. And I just didn't want that.

"To be honest, I also didn't always find the company that congenial. There's a lot of bitchiness and envy among academics, and I had just had enough of the internal politics."

It wasn't easy giving up the financial security - "my wife still hasn't entirely forgiven me" - but he has no lingering regrets. He now has the freedom to go to Borough market every Friday morning, to go fishing and, most of all, to write and say what he likes.

His latest book, Blood & Rage: A Cultural History of Terrorism, is a case in point. Where other scholars tend to be somewhat guarded in their writings, trading mainly in qualifications and footnotes, Burleigh is refreshingly willing to let rip. And his main target is the wishy-washy relativism of many people on the left in their attitudes to terrorism.

For Burleigh, there are no fine lines to be drawn. One man's terrorist is not another man's freedom fighter; one man's terrorist is another man's terrorist.

"It's nonsense to talk about the war on Islamic terrorism as a clash of civilisations," he says. "The distinction is between civilisation and chaos. Whatever people may claim - and the desire to cut through the political processes can be very powerful - there is never any justification for violence."

It sounds uncompromisingly hardline, and his critics have been queuing up to portray him as "Mad Mike", blood brother to his fellow Daily Mail columnist "Mad Mel". But while he may resemble historians such as Niall Ferguson and David Starkey in his political affiliations, it's a mistake to pigeonhole him as a gobby, rightwing apologist.

If you bother to read what he has actually written, you find a liberal beating heart. Three of his recent Mail columns - in which he argues strongly against the west's use of torture, the Saudi monarchy, and threats to bomb Iran - wouldn't have been out of place in these pages. And alongside the polemic of Blood & Rage runs a finely nuanced argument that gets underneath the skin of accepted opinion.

Terrorists as individuals

Burleigh treats terrorists as individuals, balancing their motivation against their actions. And what he finds drives them is, at best, a perverted sense of altruism and, at the most basic level, an intoxication with excitement and mayhem.

"It's no coincidence," he observes drily, "that most terrorists are males aged between 18 and 30. One terrorist from the 1960s recently said, 'we half-read a whole lot of theories that we fully understood' - and the same probably applies to Islamic terrorists today. Few have any background in religion, and most are ignorant of Islam. They've just ingested it as slogans, either from the internet or radical clerics, and attached it to some grievance about the persecution of Muslims in other parts of the world."

Burleigh is quick to stress that many of the grievances are completely legitimate; he takes issue only with the means by which terrorists seek to resolve them.

He also believes that the west needs to take greater responsibility for its own actions, pointing out that Muslim extremism is not a new phenomenon. It just feels that way because, as long as the violence was "out there" somewhere and didn't impact directly, the west was happy to ignore the growing sense of deprivation and frustration among many Muslims.

And even now that the west has well and truly woken up to the threat, it's reactions to terrorism are inconsistent.

"Earlier this year, a terrorist group persuaded two women with Down's syndrome to become suicide bombers, killing 90 people in Baghdad's pigeon market," Burleigh says.

"What kind of sick person can do that? Yet the story made only a few paragraphs in the foreign news. Where was the west's sense of outrage? We should be equally appalled by Muslims killing other Muslims as by Muslims killing Christians and Jews."

Coming up with practical solutions is less easy. "Policing terrorist groups that have no formal structures and auto-radicalise via the internet is almost impossible," he concedes.

"But we could start by getting ridding of the obvious contradictions in our own foreign policy. We can't expect our promotion of democracy in the Middle East to be taken seriously so long as we turn a blind eye to the authoritarian Saudi government because we're dependent on it for oil and arms deals."

Blood & Rage is far from the last word on terrorism, as Burleigh readily accepts, but he isn't that bothered. He'd much rather get his oar in with a first draft of history than tear into someone else's work. Not out of vanity, but because he has a low boredom threshold.

"I've always been much more interested in what I don't know rather than what I do," he smiles.

Either way, it's an approach that's paid off. His career has been punctuated by accolades and prizes, and he's as well known outside academia as he is within it. But it hasn't always been a comfortable ride; his enemies still can't quite forgive him for having a successful career outside the confines of the university and even his friends sometimes give him a hard time.

"I was recently invited to a conference by the Dutch Royal Historical Society, where they were discussing my work," he recalls with a slight groan. "And they spent the whole day criticising me."

You don't survive for more than 20 years as an academic without developing a thickish skin, though. And you suspect that however irritated Burleigh may get about the way he is misrepresented, he would be even more annoyed if he were ignored completely. In any case, it's not as if he doesn't make himself a large target: while many historians get cornered into specialist areas, Burleigh has covered everything from the medieval period to the present day.

Logical progression

It may sound a bit scatter-gun, but there has been a logical progression to his career, with one project opening up to another. "My first book was a detailed work on Germany's links with the east, in which I unintentionally managed to stitch up the entire upper echelons of the German historical establishment," he says.

"I started the project by aimlessly going through the archives of all academics who had been aged between 20 and 40 in the 1930s, to find out what they had done under the Nazis. As I had started my career as a medievalist, I had no idea who the important German historians of the 20th century were, so it was only by accident I discovered the appalling things that the German equivalents of Hugh Trevor-Roper had done and covered up. For some reason, that was one of my books never to be published in Germany."

It sparked research into the working lives of the medical profession in the Nazi era, which led to books on the euthanasia programmes and the disabled.

When his agent suggested he write a definitive book on the Third Reich, Burleigh initially refused, believing there were enough definitive books on the Nazis already, and that everything that could be said had been.

All that changed with a single thought: what if you were to explain the Nazi phenomenon, not so much a political ideology, but as a surrogate religion, wrapped up in stylised and sentimental rituals?

This eventually developed into the bestselling Third Reich: A New History, and from there it was a comparatively easy leap to explore the role of religion in a much wider context throughout history in Earthly Powers and Sacred Causes.

"Historians have widely ignored the impact of man's need for something to believe in, and how that can be manipulated," he explains. "People want a simple narrative; they want a magic young prince to save them. You can see this with Barack Obama in the US: if you actually look at what he's about, it's just make believe. The idea that he could persuade the leaders of Iran and Syria to sit down at the same conference table is absurd."

Burleigh grew up on the south coast near Pevensey Bay, and the close proximity of Roman forts, Norman castles, Napoleonic Martello towers and second world war pillboxes first made him aware of the passing of time. His interest was fuelled by his history teacher, a war veteran with a gammy leg, and he eventually wound up at University College London, where he chose to read medieval history precisely because it was a period about which he knew nothing.

"London university was truly collegiate in the 1970s," he says, "and the history faculty read like a Who's Who of the great and the good. I can still remember my first art-history seminar, because I was the only person to turn up as the time had been changed. I ended up having a private tutorial with Ernst Gombrich and two other members of staff."

And that's as misty-eyed as Burleigh gets about university life these days. His time is now divided between thinktanks, the Hoover Institution - "where else can you bump into Colin Powell and George Shultz for a chat?" - and writing. With a new chapter of Blood & Rage to complete for the US edition, he's reluctant to talk too much about future plans beyond saying he wants to do more work on terrorism and moral combat.

"I'll tell you what I won't be doing," he says. "I won't be doing any more documentaries for TV. The budgets are just too small. I realised I had hit the nadir last year in Camden Lock, when the film crew had to purloin a shopping trolley from Morrison's to cart the equipment around."